To investigate the relationship between the tearing success rate of the E-flute zipper lines and the forward cut length of these zipper lines, the forward cut length was changed in the tearing test while maintaining the connecting portions’ length (uncut length) at 3.0 mm, the width of the zipper band at 12.0 mm, and the pulling velocity at 1.0mm/s. The experimental results show that the tearing success rate of the connecting portions increases with the increase in the forward cut length due to the increasing of the horizontal (in-plane) shear displacement by the vertical (out-of-plane) uplift of the forward cut zone band. The lower and upper complementary-critical lengths of 5.0 and 9.0 mm of the forward cut length, respectively, against the uncut length of 3.0 mm were revealed. Two kinds of bent-dented wrinkles and the corresponding two patterns of the tearing force were observed. These are statistically determined by the crossed (glued) position of the corrugated medium and upper/lower liner against the starting /ending position of the connecting portion.

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Biomass plastics are attracting research attention owing to the growing environmental problems caused by plastic products. In this study, we investigated the effects of counter cations on the gas-permeation properties of hydrogen, oxygen, nitrogen, carbon dioxide, and methane in the membrane state of alginic acid (Alg) and sodium alginate (Na-Alg), in which the hydrogen atom of the carboxy group of Alg from seaweed is replaced with sodium, as well as ammonium alginate (NH4-Alg), in which it is replaced with ammonium ions. These polysaccharide membranes exhibited permeation behavior based on a solution-diffusion mechanism similar to that of common polymeric membranes. Using Alg as the standard, the counter cations in the Na-Alg and NH4-Alg membranes affected the aggregation structure of the polymer chains and contributed to the construction of a densely packed membrane structure. These polysaccharide membranes can be used as gas-barrier layers for earth-friendly industrial applications such as packaging.

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